Safety control for gaseous fuel burners



NOV. 7, 1944. w JACKSON r 2,361,944

SAFETY CONTROL FOR GASEOUS FUEL URNERs Filed May 14 1941 3 Sheets-Sheet1 5m 27 flai Q '1 1 19 INVENTOR. 106% L v -W/LBUR E JACKSON? L T BY WinsI-LJ'EFFERS 6- ATTORNEY Nov. 7, 1944. w. F. JACKSON ETAL SAFETY CONTROLFOR GASEOUS FUEL BURNERS 3 Sheets-Sheet 2 Filed May 14 1941 WNW 1944- w.F. JACKSON El'AL 2,351,944

SAFETY CONTROL FOR GASEOUS FUEL BURNE1iS Filed May 14 1941 3Sheets-Sheet 5 V 'I/l/ v 4,

INVENTOR.

WILBUR E JACK6ON8/ BY Worms H. Straws ATTORNEK Patented Nov. 7, .1944

UNI-TED STATE REISSUED 'wllbur F. Jackson. Lynwood. and mm a.

Jeflers, Los Angeles, Calif., auignors to Grays'on Heat Control, Ltd,poration of California V Application May 14, 1941, Serial No. 393,396

12 Claims.

This invention relates to safety controls for gaseous fuel burners andmore particularly to controls for domestic water heaters and the like.

Fuel controlling devices have been proposed to permit manual opening ofthe pilot burner fuel passage and automatic opening 01 the main burnerline only after the pilot burner is lighted. In normal operation thefuel supply to the main burner is thermostatically regulated .to main-.tain'the water to'be heated at a predetermined temperature. Should .theflame of the pilot burner be extinguished for any reason, the fuelsupply to both the main and pilot burners is shut oil, and no fuel canflow through either burner until the device has been manually reset andthe pilot burner relighted. Such safety devices have, however, involvedthe use of several valves which complicate the structure and detract"from its efliciency in'operation.

It is an object of this invention to reducethe number of parts requiredin such controls, while retaining the safety features thereof.

Another object of the invention is to ensure positive operation of thesafetydevice when required. i

Another object of the invention is to avoid incomplete shut- 011 of thefuel, such as may be due to deposit of dirt between the valve seating"surfaces.

Another object of the invention is to shut off the flow of fuel toboth'the main and pilot burners when the safety control operates.

Another object of the invention is to prevent operation of any othermanual control which may be provided until after the manually controlledp lot burner has been lighted and the automatic safety control isoperating.

Another object of the invention is to combine shut-oil, safety andthermostatic regulating devices into a simple, compact and reliablestructure permitting economy in manufacture and facilitatinginstallation and repair. v

Other object and advantages will become apparent from the followingdescription taken in connection; with the accompanying drawings,

wherein Fig. 1 is a, plan view of the improved control;

Fig. 2 is a 'side elevation;

Fig. 3 is an and elevation;

Fig.1 4 is av longitudinal sectional view;

Fig. 5 is a section taken on the line 5-5 of Fig. 4 looking inthedirectionindicated by the arrows;

Fig. 6 is an enlarged section taken on the line ll port 27,,

"AR 1 6 i948 Lynwood, Calif a cor- 3-3 of Fig. 3 looking in thedirection indicated by the arrows;

Figs. 7. 8 and 9 are partial sections taken along the line l--1 of. Fig.4 and showing different ,positions of the shut-off valve; and

Figs. 10, 11 and 12 are partial sectional views taken along the lineIll-40 of Fig. 4, showing the relative positions of the interlockingdevice for the shut-oil valve when the latter is in the positions ofFigs. 7, 8 and 9, respectively.

' Referring more particularly to the drawings, the control comprises acasing I! provided at one end with a laterally extending intake nipplel1 and, at the other end with an outlet nipple i9 adapted to beconnected by suitable pipingwith the main or heating burner of the waterheater or other appliance (not shown).

The upper portion of the casing I5 is shaped to provide a tapered valveseat 2| within which a tapered plug cock 23 is seated. The plug cock 23is provided with an axial bore 25 with which La port 21, extendingthrough one wall of the cock 23, communicates. The port 21 aifordscommunication between the inlet nipple l'l and the bore 25 in order that,the fuel may flow into the body of the casing I! when the cock is inthe by a retainer plate 33 secured to the casing I! by I means of thescrews 35 and overlying the shoulder 33 formed by the junction of thereduced stem 23 with the cock 23. A spring 31 is housed within a recess33 at the junction of the stem 23 with the shoulder 30 and, by itsengagement with the overlying portion of plate 33, serves to maintainthe cook 23 resiliently in its seat 2|. A stationary reference point inthe form of a depending flange 33 on plate 33 i provided to cooperatewith the dial 3| as hereinafter described to indicate the variouspositions of the cock 23.

Rotation of the cock 23 in its seat is limited to substantially betweenfull-open and fullclosed positions by the provision of an upstandingflange III on the plate 33 which enters the underside of the dial 3i andengages with either end of an arcuate abutment 42 formed thereon. Thestem 29 of the cock is provided with a threaded bore 44 for thereception of an adjustable plug 43 which extends into the bore 23 andserves to regulate the flow of fuel through the 'I'he shut-on cock,which is constructed as described, is adapted for controlling fuel flowfor both the main and pilot burners of the appliance. The pilot controlincludes an arcuate groove 48 formed in the seating surface of the cook28 opposite the port 21. The seat 2I is provided with a similar butshorter arcuate groove 58 communicating with the inlet nipple II. Apassage 82 extends from the seat 2I adjacent the groove 58 andcommunicates with a passage 54 extending obliquely across the casing I5and terminating in a horizontal passage 88.

By referring to Figs. 7, 8 and 9, the flow of fuel in various positionsof the shut-off cook 23 may be ascertained. In Fig. 7 the cock is shownin closed position designated by a notch 58 on the edge of the dial 3Imarked "Off" (Fig. 1) and there is no communication between the inletnipple I1 and the port 21 or between the arcuate groove 48 and thepassage 52. Upon being rotated from the closed position the cock firstreaches the pilot position, designated by a notch v88 on the edge of thedial 3|, marked Pilot (Fig. 1). This position is shown in Fig. 8 and thearcuate groove 48 is now in communication with the passage 52. The nextposition of the plug cook 23, upon further rotation, is the "on"position suitably designated by the notch 82 in the edge of the dial 3Iand marked On. This position is shown in Fig. 9 and the port 21 in thecock communicates with the inlet nipple I'I while at the same timecommunication between the passage 82 and the inlet nipple I1 isafl'orded by the arcuate groove 48 extending across both the passage 52and the groove 58 in the valve seat.

In order to facilitate positioning of the dial 3| in the pilot positiona non-positive stop is provided which, as shown in Fig. 3, comprises aplunger 84 mounted within an aperture 88 formed in the underside of thedial 3| and yieldably urged into engagement with a depression 88 in theplate 33 by means of the spring I8. Thus, the "on and '01! positions ofthe shutof! cock are located by the positive stop and the pilot positionby both an audible click and increased resistance to rotation of thedial afforded by the device described.

An end casing 58 is secured to the main casing I5 by means of the screwsI2, and a gas-tight joint secured by the provision of a gasket I4between these members. As shown in Fig. 6, the end casing 38 is providedwith an adjustable plug I8 having a hollow threaded end I8 reclprocablein a threaded passageway 88 communicating with the passage 88 in themain casing. The hollow end of the plug 18 communicates with an aperture82 in the plug body which may be moved into and out of registry with apassage 84 formed in the end casing 58. As will be apparent, rotation ofthe threaded plug will increase or diminish the eiIective area ofaperture 82 and adjust the amount of fuel that flows through the passage84.

The passage 84 communicates with a chamber 88 within which a pilotcontrol valve 88 is housed. The pilot control valve 88 may be of anysuitable form and, in this instance, is shown as being of the poppettype adapted to be moved into and out of engagement with its seat 88against the pressure of a coil spring 92 retained in thechamber 88 bythe cap 84. The stem 88 of the pilot control valve 88 is suitablygrooved to permit the passage of fuel therearound and is guided in anopening 88 formed in the end casing. A sealing chamber I88 receives theprojecting end of III the valve stem 88. Intermediate the chamber I88and the valve seat 88 is an angular passage I82 communicatin with apassage I84 formed in the main casing I5. The latter passagecommunicates through a suitable coupling connection I88 with a conduitI88 connected as shown in Fig. 4 with a pilot burner II8. In order thatleakage of gas from the pilot control valve chamber 88 into the maincasing I5 may be prevented the valve stem 98 is provided with aprojection II2 which engages a cap I I4 carried by a diaphragm I I8extending across the end of the sealing chamber I88 and secured inengagement therewith by means of the threaded collar H8. The cap I I4serves to reinforce the center portion of the diaphragm which receivesthe pressure of the operating parts.

As shown in Fig. 3, the pilot control valve assembly described is housedwithin part of the end casing 88 and is positioned to one side of thevertical axis of the main casing I5. That portion of'the end casing 58which is adjacent the vertical axis of the main casing I5 is providedwith a chamber I28 (Fig. 4) within which a thermoelectric assembly isadapted to be housed. This assembly includes a horseshoe electromagnetI22 seated on its base I24 in an end cap I 26 secured by screws I 21 tothe end casing 58 and forming a closure for the opening I28. In order tosecure the magnet I22 yieldably in position and prevent distortionthereof, a coil spring I 28 is held in position on the magnet base I24by means of a magnet retainer I38 secured by means of the screws I32 tothe end cap I28. A stem I34 extends between the legs of th magnet I22and through the magnet retainer I38, there be ing an aperture I38provided in the magnet base I24 to permit further extension of the stemduring operation of the device. The stem carries an armature bar I38,abutting a flange I48 on the stem, and adapted to bridge the poles ofthe magnet I 22 in the usual manner. An armature stem spring I42 extendsbetween the nut I48 and the magnet retainer I 38 and serves to urge thearmature bar I38 away from the poles of the magnet I 22. In order toprevent the spring I42 from unseating the magnet from the end cap I 26,the spring I28 may be made considerably stronger than the spring I42.

The arms of the horseshoe electromagnet carry the coils I44 of a wireI48 which is connected by soldering or other suitable means to the headI48 of a terminal screw I58, the opposite end of the wire being securedto the magnet retainer I38. As shown in Fig. 6, the terminal screw I58extends through the end cap 58 and emerges from the main housing I5 at apoint behind the connection' for the pilot burner conduit I88. Theterminal screw I58 is insulated from the body of the casing by thesleeve I52 and the terminal insulator I54.

A terminal sleeve I56 having a threaded end I58 is screwed into the endcasing 58 around the insulating sleeve I52. A portion I59 of theinsulating sleeve projects beyond the terminal sleeve and the terminalscrew I58 projects still further. The projecting parts form terminalsproviding suitable electrical connection for the two elements, I88 andI82, of a thermocouple, these elements being separated at the terminalsby means of the insulating washer I84.

The thermocouple may be supported by a bracket I88 in position to beheated by the pilot burner II8, thereby to establish an electric currentto the coils I44 of suflicient strength to enersize the mag et I 22 andhold the armature bar j as sts as m contact with the ooierooos'tnreoruaiqst the force of the spring I42 provided that then:-

mature bar has been moved intocontact withfthe magnet in a manner -whichw il l "now be :exf

plained. a a Formed in the end-casing "immediately above the chamber I20for the thermoelectricassembly andon substantially the same verticalaxis, is a smaller chamber I88 within which a reset button 7 10 I10 isslidably mounted. This reset button carries a reset stem I12 extendingthrough anaperture inthe bottom wall of the chamber I88 and having aprojecting end I14 extending into the main casing I adjacent the taperedopening'ot the valve seat 2 I. The reset stem "2 is provided with acollar I18 between the stem and its projection I14. A coil spring I18acts between the reset button I and the end wall or the opening I88 tourge the button outwardly from the opening, this movement being limitedby. the engagement of the collar 8 with the end wall. springwill causereturn of the button I10 to the position shown in Fig. 4 after ithasbeen manually depressed and released.

The projection I14 cooperai s with the end of the shut-oil cook 23 toprevent manual actuation of the reset button I I0 except when the cockis in one position. The three positions of fullclosed, pilot andfull-open with the position of the projection I14 are shown'in Figs. 10,11 and 12, respectively. To this end, the cock is provided with a slotI80 which is so related to the arcuate groove 48, inlet nipple I1 andaperture 82 previously described, that when the dial is moved to thepilot position the slot will be aligned with the projection "401 thereset stem, as shown in Fig. 11.

This invent'on is particularly directed toward the provision of but asingle valve for providing both thermostatic control of the main burnerand safety control of the flow of fuel thereto should the "pilot burnerbecome extinguished. Accordingly, the body of the main casing I5 is ofhollow form below the portion carrying the plug cock 28 and is providedwith a web I82 within which of fuel through the ports I92 in the valveseat to the outlet nipple I9, with which these ports are aligned. Itwill be observed that the valve assembly is axially aligned with thethermoelectric assembly with which it is operatively associated. V I w jThe hollow valve stem I 88 contains a spring I04 which servesto urge aplunger I88 intocon 80 tact with a plug I98 closin'g'the inner end orthe hollow valve stem. I The "reduced end ofthe plunger I98 projectsthrough the plug and is adapted to engage and be qperated by a clickermechanism comprised of a pair of opposed ful- 08 crum levers 200,fulcrum button 202 and clicker disc 204,-all of which are housed withina recess 205 formed in the annular valve seat I84. 4 Thermostatic meansfor operating the valve vided and consists of'an element or the rod-andtube type. A tube 2080f material having a high coefilcient of expansionis securely mounted at its inner end on the casing I5. The rod 208 orthe 8 2881s recessed for Thus the mg a'lowooeliicient or the tube 288one is; threadedlyf {at its outer end with a plug 2 I8 anchoredthefouter end 01' the tube 288." The inner n oifthe rod w a nii o ientsecured in positionbyfmeans ora p1 H cap 2I4' engages a-sealing 2 Iflsecredfinfa recess m in thecasins n by t val seat up and having its innerportion urgedi ofenga'ge mentlwith a thrust member '2'I8'byjthecap'inember24. As is well known, the differential in the expansion of the rodand tube under the influence of the heat '01 the water in which thedevice is mounted causes the rod to actuate the thrust member 2 tooperate the clicker disc 204 which, in turn; operates the fulcrum button202 and the opposed fulcrum levers -200. The levers 200 strike theplunger I88 which actuates the valve member I80 to open position, itbeing noted that the spring I84 is not compressed at this time as willbe apparent hereinafter. Suitable means for mounting the control in thewater heater or other appliance are provided by the elongated boss 220projecting from the casing around the rod and tube element. Thetemperature at which the valve I80 will be operated may be adjusted bymeans of a manually operated lever 222 attached to the rod 288 by meansof the set screw 224. The lever carries a pointer 228 forcooperationwith indicia 228 on thecasing. Movement or the lever in avertical direction will serve to rotate the rod 288 and screw this rodfurther in or out of the plug 210 to change theexpansion differential. I

Movement of the valve I80 toward and away from its seat by thethermostatic ,device is governed by the condition of the thermoelectricmechanism previously described. Such governing action is eiiected by theprovision '01 valve operating mechanism fcr the thermoelectric assemblywhich will now b described. The armature stem I84 is provided beyond thearmature bar I88 with an extension having a threaded end 280. Mounted onthe end 280 is an abutment member 282 having an annular recess 284intermediate its ends. The abutment member 282 is suitably grooved toreceive one end or a spring 288, the other end or which engages with thevalve I80 urging it toward its seat.

The threaded extension 280- of thefannature stem also carries a collar288 slidabiy' mounted within a guide disc 248 which, togetherwith aflexible sealing disc 242 carried on the stem. is securely retained inposition across the end of the chamber I20 by means or the threadedcollar 244. As will be apparent; the function of the sealing disc 242 isto prevent the entrance of fuel into the magnet chamber I20, while ,atthe same with the'poles of the magnet I22.

Extending betweenythe projecting ehd I14 of bar toward and away.fromattracted position the reset stem and the recess 2'841 ih';the.abut-" ment member 282 'is a"pivotedflever 248.1 As

shown in Fig. 5, this lever is pivotally mounted intermediate its endson aQpin-"ZABTIcarried by.

I spaced lugs 250 onftheinnerff'ace of'theendfcase stem extension I14"is curved to slidably engage the extension I14" for this purpose.

end of the lever isalso slotted to extend around thermo-responsive unit,which is of material havthe recessed p tion 184 of the abutment 282 andtime premitting freemovement ofthe armature ing as. The one or the leveradjaentjthefresetf I through the clicker disc mechanism is pro-'- 70 issimilarly curved for slidable engagement with the walls of the recess234. The lever 240 is further provided on one side with a radiallyextending arm 254 which is adapted to engage at its outer end with thecap member I I4.

To operate the control from the o position on the dial, as shown in Fig.'7, the dial is first rotated to the pilot position. Until this positionis reached, no gas can pass the shut-oil? cock and both the pilot andthe main burner'control valves are in closed position.

In the pilot position, as shown in Fig. 8, the fuel may flow from theinlet nipple I! by way of the arcuate groove 46 to the pilot passage 52and.

thence to the pilot control valve 88which, as stated, is in the closedposition. At this time the slot I30 in the lower portion of the shut-oi!cock 23 is in alignment with the extension I I4 of the reset stem I12.The reset button I is then manually actuated to depress the stem I12 andcause the extension I14 to enter the slot I80, as shown in dotted linesin Fig. 11. When the reset button is thus operated, the collar I16 onthe stem I12 engages the curved end of the lever 246 and moves it in aclockwise direction, as viewed in Fig. 4, around the pin 246 as thefulcrum.

While the reset button is thus being actuated, the pilot control valve88 is moved oil its seat by the engagement of the lateral arm 254 withthe cap II4 on the end of the valve stem. Hence, gas is allowed to flowpast the pilot control valve 88 and through the passages I02 and I04 tothe pilot burner H0. The pilot burner may then be lighted and the flamesize adjusted by operation of the adjusting screw I6. Due to the centralpivoting of the lever 246 the lower end thereof will move in theopposite or clockwise direction when reset button I10 is depressed. Thusthe lower end of the lever 246 acts against the lefthand wall of therecess 234, as viewed in Fig. 4, and forces the armature bar I36 againstthe pole faces of the magnet I22. The flame from the pilot burnerimpinges upon theend of the thermocouple which is connected in serieswith the coil I44 of the electromagnet I22.

In a short time the thermocouple generates sufficient current toenergize the magnet and maintain the armature bar I38 in contact withthe pole faces thereof. The reset button may then be released but thelever 246 remains in' pivoted position being maintained by the recess234 in such position. Consequently, the lateral arm 254 continues tohold the pilot control valve 86 in open position and the abutment 232remains stationary and spaced from the valve member I90. The position ofthe parts is as shown in Fig. 4, where the control device is in theoperating position and the valve I90 free to be moved on its seat by thethermostatic control to permit flow of gas in the main burner.

To cause gas to flow to the main burner, the dial must be moved to theon" position, as shown in Fig. 4 and Fig. 9, permitting gas to flow fromthe inlet nipple I'I through the port 21 of the gas cock into the mainbody of the casing I5. In this position it will be observed that thegroove 50 permits gas to flow to the pilot burner by connecting groove48 with the inlet II. The indicator lever 222 may be set to the desiredtemperature indicated on the casing and the control will then be incomplete operation.

As previously described in part the rod 208 of the thermostatic meanswill actuate the valve I90 with a snap action through the clickermechanism provided. The movement of the plunger.

provided to, permit the fulcrum levers to move under thermostaticoperation when the valve is being held closed by the safety mechanism.

In the event that the pilot burner is extinguished, the thermocoupleceases to generate cur- --rent, causing deenergization of theelectromagnet and movement of the armature bar I36 away from the polefaces. Such movement of the armature bar is caused by the spring I42which urges the abutment 232 toward the ,valve member I90. If thethermostatic mechanism is operating at this time to hold the valve I inopen position, movement of. the abutment 232 will serve to close it.Such action is due to the spring I42 on the armature stem being strongerthan the spring I94 in the valve stem. and thus overcoming it to movethe valve I90 to closed position. During this movement of t e abutment232 toward the right, as viewed in g. 4, the lever 246 is rotated on itspivot 240 in a counter-clockwise direction. The laterally extending arm254 moves away from the cap II4 on the pilot control valve and thespring 92 for this valve moves it to closed position. Thus, when thepilot burner is extinguished ,for any reason the safety mechanismoperates to close both the main control valve I90 and the pilot controlvalve 60, giving a complete shut-oil.

It .will be apparent that if an attempt were made to set the safetymechanism in any other than the correct way, as outlined hereinbefore,the construction of the control would prevent such operation from beingcarried out. The reset button I10 cannot be depressed if the dial is inany position other than the pilot" position. The parts are constructedand arranged so that the end of the reset stem extension "4 will strikethe flange on the bottom of the shut-oil cook 23 before the collar I16on the stem can engage the upper end of the lever 246. Thus, neither themain control valve nor the pilot control valve can be opened with thedial in any other than the pilot position.

It will be appreciated that the valve I90 is operated by thethermostatic mechanism under normal conditions but this mode ofoperation is supplanted by that of the electric control wheneverconditions demand. If the thermostatic control, is holding the valve I90oil" its seat and the safety mechanism comes into operation, thethermoelectric control overcomes the action of the thermostatic control,causing closure of both the main and pilot valves as described. Thus,the thermoelectric control is, in effect, a governor for thethermostatic control which normally operates the valve controlling fuelflow to the burner.

In controls where two or more valves are used in place of the singlevalve described and shown herein, the thermostatic valve is usually inconstant operation but the safety valve is called upon to function onlyinfrequently. It is apparent that unless abnormal conditions arise thesafety valve has no occasion to operate. As this safety valve usuallyremains stationary for long periods-of time it becomes incapable offunctioning efliciently when called upon to do so. An infrequentlyoperated valve is subject to gumming due to the drying of lubricants andalso to dirt from the gas being deposited on the seating surfaces.

Such condition of the safety valveawould not be discovered until theleakage became apparent. In the device described and. shown herein, thesingle valveis in oonst'antoperatlon as a thermostatic valve and, whenthe thermoelectric safety device becomes operative, it acts upon thisvalve Closure of this'valve by the safety control is readilyaccomplished due to the absence of dirt on the seating surfaces and theoperative condition in which thevalve has been retained. It may be notedthat the continual opening and closing of such a valve will tend to makeit self-cleaning.

The embodiment of the invention herein shown and described is to beregarded as illustrative only, and it is to be understood that variousmodifications and changes may be made within the scope of the appendedclaims without departing from the spirit'of this invention.

We claim:

1. In asafety control for gaseous fuel burners, the combination of amain fuel valve movable between positions for controlling supp y of fuelto the burner, a control valve positioned normal to said'main valve forintercepting the supply of fuel to the burner, electromagnetic means inaxial alignment with said control valve and adapted to govern theoperation thereof, manually actuable means extending substantiallyparallel with the axis of said control valve and into the path ofmovement of said main valve to set said electromagnetic meansfor'goveming operation, said manually actuable means being operable inonly one position of said main valve, and a pivoted member extendingbetween said electromagnetic and manually'actuable means fortransmitting movements of one to the other. i u

2. In a safety control for gaseous fuel burners, the combination of amain fuel valve, a thermally operated control valve intercepting thesupply of fuel, a pilot burner having communication with said mainfuelvalve, means responsive to,

re, movable to s at lamina es tuable for simultaneouelymoving said at,-mature and operating said pilot burnermeans for overcoming the biasingmeans for the main controlling means and operating sai means to permitfuel supply to the mainburnenand means associated with said armature andmovable therewith into and out of operative engagement with said maincontrolling means for permitting\op'- eration of said main controllingmeans to supply fuel to the main burner onlywhen said armature is inattracted position.

5. In a safety control for gaseousfuel burners having main and pilotburnersjthe combination of a main fuel valve, a-main control valve meanspermitting operation of said maincon trol valve to supply fuel to saidmain burner only when said armature is in attracted position, and meansassociated with said main fuel valve permitting operation of saidmanually actuable means only when said main valve isin one position.

6. In a safety control for gaseous fuel burners having main and pilotburners, the combination of a main fuel valve, a thermally Operatedvalve intercepting the supply of fuel to the main burner, a pilot burnercontrol valve intercepting the supply of fuel to the pilot burner,thermoelectric means energizable by said pilot burner and having anarmature movable to attracted position,

the presence of a flame at said pilot burner for governing the operationof said control valve, manually actuable means for setting said flameresponsive means for governing operation, means for preventing operationof said manually actuable ineans when said main fuel valve is in openposition, and manually actuable means to set the temperature at whichsaid control valve will be operated. n

3. In a safety control for gaseous fuel bumers, the combination of amain fuel valve,a thermally operatedcontrol valve intercepting thesupply of fuel to theburner, thermoelectric means adapted to govern theoperation of said control valve, manually actuable means to set saidthermoelectric means for governing operation, means for preventingoperation of said'manually actuablemeans when said main valve is in openposition, and manually actuable means to set the temperature at whichsaid control valve will be operated.

4. In a safety control for gaseous fuel burners having main and pilotburners, the combination of a main fuel valve Governing the supply offuel to both the main and pilot burners, means for controlling thesupply of fuel from the main valve to the main burner, means forcontrolling the supply of fuel from the main valve to the pilot burner,blasingmeans for each controlling means urging the same to a positionwhere fuel supply is prevented, thermoelectric means energizable by saidpilot burner and having an armaply of fuel to the main manually actuablemeans for simultaneously moving said armature and operating said pilotcontrol valve. means permitting operationof said thermally operatedvalve tofsupply fuel tosaid main burner only when saidarmatureisin'attracted position, and means associated with said mainfuel valve permitting ually actuable means only when said main fuelvalve is in one position.

7. In a safety control for Gaseous fuel burners having main and pilotburners, the combination of a main fuel valve having a pilot position, athermally operated valve intercepting the supburner, a pilot burnercontrol valve intercepting the supDLv of fuel from said main fuel valveto the pilot burner, thermoelectric means eneraiza le by 1d Pilotburner. an armature for said thermoelectric means movable between freeand attracted positions, means extending between said, armature and saidthermally operated valve to retain said valve in a closed positionwhensaid armature is free, manually actuable means for simultaneouslymove ing said armature to attracted position and op erating said pilotcontrol valve to open position, and means associated with said main fuelvalve permitting operation of said manually actuable means only whensaid main fuel valve is in pilot Position.

8. In a safety control for gaseous fuel burners having main and pilotburners, the combination of a main control valve for the main burner, apilot control valve for the pilot burner, biasing means for each valveurging the'same to closed position, thermally responsive means forovercoming the main valve biasing means and actu-' ating said valve toopen position, spring means operation of said maninterposed between saidthermally responsive means and said main valve, safety means operable inopposition to said thermally responsive means and in cooperation withsaid biasing means upon the main valve to compress said spring andreverse the position of said main valve from open to closed, means foropening the pilot control valve and actuating the safety means to aposition permitting the thermally -responsive means to actuate the mainvalve, and means responsive to the presence of a flame at the pilotburner for holding the last said means in said position.

9. In a fuel control device, the combination of a casing forming aconduit supplying fuel to a main burner, a pilot burner having a fuelsupply connection separate from the conduit, a valve mounted in thecasing for controlling the fiow of fuel in the conduit, snap-actingmeans biasing said valve to a position where passage of fuel to the mainburner "is prevented, thermostat means associated with the snap-actingmeans and responsive to heat fluctuations caused by the main burner forreversing the position of said snap-acting means and holding the valvein a position where passage of fuel to the main bumer is permitted, andseparate valve closing means responsive to absence of heat from thepilot bumer to overpower the thermostat means and reestablish the biasedposition of the valve, said means comprising a plunger cooperable withthe snap-acting means for moving the valve to biased position, a magnetfor holding the plunger in position to permit reversal of the positionof the snap-acting means, and a thermocouple exposed to the heat of thepilot burner for energizing the magnet.

10. In a safety control for gaseous fuel bumers, the combination ofmeans movable between positions for controlling the supply of fuel tothe burner, actuating means for said fuel controlling means positionedfor operation on one side thereof, means biasing said fuel controllinmeans to a first position where suppl of fuel to'the burner isprevented, yieldable means intersaid first to a second position wherefuel supply is permitted, and thermally responsive means adapted toexert sufficient force upon said controlling means from the oppositeside to said actuating means to cause return or said control ling meansfrom said second to said first position-to cut off the fuel supp y tothe burner, said yieldable means being adapted to absorb the force ofthe first said thermally responsive means upon said return operation.

11.. A safety control for fuel burners having main and pilot burners,comprising a body memthereto for operation from one side of said seat,

yieldable means interposed between said actuating means and valve memberand operative to vary said relation, thermally operable means responsiveto the main burner for causing operation of said actuating means todisengage said valve from its seat while said yieldable means remainsinoperative to vary said relation, and means responsive to the absenceof heat at pilot burner adapted for operative engagement with said valvemember from the opposite side of said seat for returning said valvemember into engagement with said seat, said yieldable means becomingoperative to vary said relation thereby permitting said valve member toreturn irrespective of operation of said actuating means tending tocontinue said disengagement thereof.

12. In a.safety control for fuel burners having main and pilot burners,comprising a body member having a passage for fuel, a valve seat in saidbody defining the inlet and outlet sides of said passage, a valve memberengageable with said seat for controlling flow of fuel from the passageto'the main burner, actuating means for said valve member positioned inspaced relation thereto for operation from one side of said seat, meansbiasing said valve member toward said valve seat and operable from theopposite side of said seat relative to said actuating means, yieldablemeans interposed between said valve member and actuating means andhaving a stronger biasthan said biasing means, said yieldable meansbeing operative to vary said relation,

means thermally responsive to operation of the main burner operativelyengaging said actuating means to exert a force thereon for overcomingsaid biasing means and disengaging said valve member from said seat,said yieldable means remaining inoperative to vary said relation duringsaid disengaging operation, and means thermally WILBUR F. JACKSON.THOMAS H. JEFFERB.

